1. Technical Field
This invention relates generally to an apparatus for providing positive recognition that a device to be retained is properly seated in its retainer, and, more, particularly to an apparatus for ensuring the wire harness has the proper number of retainers, and further for ensuring that these retainers are located at the proper intervals along the length of the harness.
2. Discussion of the Related Art
Wire harnesses, while appearing to be a relatively simply item, are often difficult to assemble. The number of wires involved, the manner in which the wires are bundled and branched from the main harness, the types of terminals that must be attached to the wires, and the number of harness retainers that must be secured to the harness greatly increase the complexity of the assembly task. As used throughout this discussion, a "wire harness" is a bundle of wires that is taped, sheathed or otherwise bundled together for routing between multiple points on a vehicle, such as an automobile; a "terminal" is a metal connection point between a wire and a connector housing; a "connector" is an interconnecting device attached to a terminal or group of terminals to facilitate the connecting of wire(s) to components or to other wires; "bundles" and "branches" within a wire harness are subgroupings of wires that are segregated from the main grouping of wires of the wire harness, usually to allow routing to separate areas, or to allow connection to terminals; and "retainers" are retention devices usually affixed to the wire harness at predetermined intervals along the length of the wire harness, where the retainers facilitate securing the wire harness along its routing path through the vehicle.
While many complex assembly tasks are now being handled by automated machinery and robots, the task of assembling wire harnesses often proves too complex to easily automate. Therefore, wire harnesses are largely manufactured by hand. However, the complexity of assembling a wire harness can often be a difficult task for the non-skilled and semi-skilled workers who frequently work on the assembly line. For these workers, the monotony of the task and the small size of the wires and terminals increases the likelihood that they may make an inadvertent error while assembling the wire harness. To aid the worker in properly assembling wire harnesses, a variety of fixtures and test devices have been fashioned.
There are several critical measurements of wire harness integrity, some of these being harness continuity, retainer presence and retainer positioning. Harness continuity is checked by determining if there is electrical continuity between each end of the harness. Usually this is done by connecting the connectors found along the wire harness to test connectors. An electrical current is then passed through the harness and is checked to see if it reaches the other end of the harness. Generally, the continuity check interrogates not only end-to-end wire circuit integrity, but also ensures that each wire-to-terminal connector connection is in the proper position. It is important to check continuity to ensure that the harness completes the proper electrical connections when mounted in the vehicle. Ensuring all of the retainers are present helps ensure that the wire harness is capable of being properly attached to the vehicle. Finally, retainer positioning along the wire harness is checked to ensure that all the required retainers are present, and that the retainers are also located at the proper intervals along the harness. It is important that all of the retainers be located at their proper intervals along the wire harness to ensure that they will mate with their corresponding receptacles on the vehicle to properly secure the wire harness to the vehicle when installed.
Ideally, it would be most efficient to be able to check for wire harness continuity, retainer presence and the interval positioning of the retainers in the same operation. Many different types of fixtures exist for checking wire harness continuity, but few currently exist for checking for retainer presence and retainer position intervals.